Thread: Air Leak on 87 Rangie

Guys,

Having some trouble sealing the plenum chamber on my 87 Rangie (EFI). I had to remove the cover to remove the LHS rocker cover and clear the vent.

On replacing the Plenum cover and re-attaching ALL the hoses, throttle etc, I have been having trouble with the engine racing at idle and hunting severely. I put my hand over the intake of the plenum chamber as well as over the flame trap hose. I have screwed the idle down to fully closed and the car still idles at 900 RPM !!

I imagine that I have a (severe) air leak arounfd the flange face between the plenum chamber and the manifold below.

My question is, how do I seal this effectively. I have tried twice with Permatec Ultra-Blue gasket maker with no luck. Is there a trick to this??

Thanks in advance

I use Stag Jointing compound or red silicone.

I find Stag good for mainfolds that don't experience a lot of heat as it seals very well and hang's on so if the bolts/nuts loosen over time the joint remains sealed.

How long did you wait before starting the motor ?

Min 10hrs I usually wait regardless of EFI, carby or mechanical injection. Haven't had any leak using either product but would suggest stag over silicone.

One other thing, did all the hoses go back exactly where they came from ie. you labelled them as they came off so they went back the same? Sometimes that can cause problems.